Placing plasmonic nanoparticles (NPs) in close proximity to semiconductor nanostructures renders effective tuning of the optoelectronic properties of semiconductors through the localized surface plasmon resonance (LSPR)-induced enhancement of light absorption and/or promotion of carrier transport. Herein, we report on, for the first time, the scrutiny of carrier dynamics of perovskite solar cells (PSCs) via sandwiching monodisperse plasmonic/dielectric core/shell NPs with systematically varied dielectric shell thickness yet fixed plasmonic core diameter within an electron transport layer (ETL). Specifically, a set of Au NPs with precisely controlled dimensions ( i.e. , fixed Au core diameter and tunable SiO 2 shell thickness) and architectures (plain Au NPs and plasmonic/dielectric Au/SiO 2 core/shell NPs) are first crafted by capitalizing on the star-like block copolymer nanoreactor strategy. Subsequently, these monodisperse NPs are sandwiched between the two consecutive TiO 2 ETLs. Intriguingly, there exists a critical dielectric SiO 2 shell thickness, below which hot electrons from the Au core are readily injected to TiO 2 ( i.e. , hot electron transfer (HET)); this promotes local electron mobility in the TiO 2 ETL, leading to improved charge transport and increased short-circuit current density ( J sc ). It is also notable that the HET effect moves up the Fermi level of TiO 2 , resulting in an enhanced built-in potential and open-circuit voltage ( V oc ). Taken together, the PSCs constructed by employing a sandwich-like TiO 2 /Au NPs/TiO 2 ETL exhibit both greatly enhanced J sc and V oc , delivering champion PCEs of 18.81% and 19.42% in planar and mesostructured PSCs, respectively. As such, the judicious positioning of rationally designed monodisperse plasmonic NPs in the ETL affords effective tailoring of carrier dynamics, thereby providing a unique platform for developing high-performance PSCs.
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This content will become publicly available on January 5, 2024
Plasmonic properties of composition graded spherical nanoparticles in quasi-static approximation
Abstract During the operation of a localized surface plasmon resonance (LSPR) sensor made in the form of a core–shell nanoparticle with the shell acting as a sensing layer, the target molecules penetrate into the shell due to intrinsic diffusion or reaction mechanisms. As a result, these molecules or various reactants are nonuniformly distributed in the shell layer. Such sensing particles are termed composition graded plasmonic particles, and their LSPR characteristics may be quite different from those of the uniform core–shell particles. Here, under the quasi-static assumption, a perturbation theory is developed to predict the LSPR properties of composition graded plasmonic particles. The effects of the composition gradient on the LSPR properties due to a metal hydride, a dielectric, and an effective medium are either numerically calculated or analytically derived. Our results show that various configurations of the composition gradient can tune the location and the amplitude of the LSPR peak. The results are important for understanding the sensing performance of composition graded plasmonic particles, and the perturbative treatment presented here can also be used for other composition graded structures.
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- Award ID(s):
- 1808271
- NSF-PAR ID:
- 10434044
- Date Published:
- Journal Name:
- Journal of Physics D: Applied Physics
- Volume:
- 56
- Issue:
- 5
- ISSN:
- 0022-3727
- Page Range / eLocation ID:
- 055102
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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